Method of manufacturing a diffuser master using a blasting agent

ABSTRACT

A diffuser master is provided which is manufactured mechanically instead of holographically. The master can be made from a suitable substrate including relatively hard materials such as plastic, glass or metal. A substrate having a first side is worked to form a diffuser surface relief structure thereon. The substrate can be buffed using a buffing agent of a selected grit in order to form surface scratches in the first side of the substrate. The substrate can also be blasted with shot particles in order to form indentations and depressions in the first side. The substrate can alternatively be acid or alkali etched in order to form surface irregularities in the first side. The scratches, depressions or irregularities can be formed in order to create a desired surface relief and hence desired diffuser output characteristics.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates generally to optical elements, andmore particularly to a non-Lambertian diffuser fabricated usingmechanical means instead of light and mechanical methods for fabricatingthe diffuser.

[0003] 2. Description of the Related Art

[0004] Methods for manufacturing and replicating optical components suchas a master diffuser exhibiting desired light diffusing characteristicsare well known. Many of these methods involve creating a master diffuserby exposing a photoresist material to a source of light and thenreplicating this master diffuser into one or more submasters of a moredurable nature. Many of these methods inherently destroy the masterdiffuser when creating the submasters. There are also other methods ofmaking replicas of a master diffuser which contain the optical featuresin the master without destroying the master diffuser. With each of thesemethods, the master diffuser is initially created optically. Submastersare created from these master diffusers utilizing a number of methodswhereby the master diffuser surface is replicated into a submastersurface. These other methods are described in one or more pending U.S.applications, referenced below, which are assigned to the assignee ofthe present invention.

[0005] One such method involves creating a submaster for an opticalproduct by recording optical features on a photosensitive medium usingcoherent or incoherent light. The photosensitive medium is then furtherprocessed to create a master optical product. A layer of two partsilicone epoxy is then poured over the master to replicate the opticalsurface features of the master photosensitive medium in the siliconeepoxy material. The silicone epoxy layer cures at room temperature andbecomes rubber. The silicone material is then further cured andseparated from the master to obtain a silicone rubber submaster. Thesoft silicone submaster is then used to make successive generations ofsubmasters or final optical products by covering the soft submaster witha layer of epoxy, covering the layer of epoxy with a plastic substrate,curing the epoxy and separating the epoxy and plastic substrate from thesubmaster. This particular method of creating a diffuser is highly laborintensive, requires use of many different materials, requires performinga number of steps, and must be conducted in a sterile environment.

[0006] The specific embodiments described above regarding the rubbersubmaster and the silver and nickel submaster are disclosed inco-pending U.S. application Ser. No. 09/052,586 entitled “Method ofMaking Replicas While Preserving Master,” commonly assigned to theassignee of the present invention.

[0007] Another method of creating a diffuser involves recording opticalfeatures in a photosensitive medium using coherent or incoherent lightand then processing the medium to create a master. The photosensitivemedium is then coated with a layer of silver. A layer of nickel iselectroplated onto the silver layer and then the silver layer and layerof nickel are removed from the photosensitive material or medium to formthe submaster. The combined silver and nickel backing form a metal shimsubmaster which is then replicated to fabricate final optical productsby embossing the surface features of the submaster into epoxies,plastics or polycarbonate materials, or by injection molding suchmaterials into a mold carrying the submaster. Again, this process iscostly, labor intensive, wasteful of material and requires a sterileenvironment.

[0008] Another significant problem with each of these methods is thatthe submasters or final optical products created from the master opticalelements are made from materials such as plastics, epoxies, orpolycarbonate composites and exhibit relatively poor long-termcharacteristics. These materials are also not suited for use nearextremely high temperature light sources because they have relativelylow melting or softening temperatures when compared to other moredurable materials.

[0009] Other commonly assigned U.S. patents and pending applicationsdisclose somewhat related methods for making and recording opticalproducts and replicating those products so that they may be massproduced. For example, U.S. Pat. No. 5,365,354 entitled “Grin TypeDiffuser Based on Volume Holographic Material,” U.S. Pat. No. 5,534,386entitled “Homogenizer Formed Using Coherent Light and a HolographicDiffuser,” and U.S. Pat. No. 5,609,939 entitled “Viewing Screen FormedUsing Coherent Light,” all owned by the present assignee relate tomethods for recording and replicating optical products. Each of theseU.S. patents is incorporated herein by reference for purposes including,but not limited to, indicating the background of the present inventionand illustrating the state of the art.

[0010] Related U.S. patent applications include Ser. No. 08/595,307entitled “LCD With Light Source Restructuring and Shaping Device,” Ser.No. 08/601,133 entitled “Liquid Crystal Display System with CollimatedBacklighting and Non-Lambertian Diffusing,” Ser. No. 08/618,539 entitled“Method of Making Liquid Crystal Display System,” Ser. No. 08/800,872entitled “Method of Making Replicas and Compositions for Use Therewith,”and Ser. No. 09/075,023 entitled “Method and Apparatus for MakingOptical Masters Using Incoherent Light.” All the above applications areowned by the present assignee and are hereby incorporated by referencefor purposes including, but not limited to, indicating the background ofthe present invention and illustrating the state of the art.Additionally, each of these patents and applications disclose methods ofmaking optical products wherein the methods or the products exhibit manyor all of the above-noted disadvantages.

SUMMARY OF THE INVENTION

[0011] A primary object of the present invention is to provide a methodfor making a diffuser optical product utilizing conventional mechanicalmeans instead of the aforementioned holographic and complex and costlymethods. Another primary object of the present invention is to provide adiffuser from an extremely durable material such as glass or metal. Itis another object of the present invention to provide a diffuser whichis suitable for use under extreme temperature conditions such asadjacent a high temperature active light source in a liquid crystaldisplay or the like. It is a further object of the present invention toprovide a method for producing such a diffuser which requires fewersteps for creating the diffuser and is less costly in materials, cost oflabor and cost of the manufacturing environment.

[0012] In accordance with the present invention, these objects areachieved by several methods for producing a diffuser from highly durablematerials such as glass or metal and by the resulting diffuser opticalproducts themselves.

[0013] In one embodiment, a method for producing such a diffuser firstincludes providing a substrate body having at least a first side. Aworking material is then selected which has desired qualities foraltering the characteristics of the first side of the substrate body.The working material is applied to the first side in order to form aplurality of irregularities thereon which define a diffuser surface. Thediffuser surface exhibits light propagating characteristics defined bythe particular characteristics of the plurality of irregularities.

[0014] In one embodiment, the working material is a buffing agent havinga desired grit. The first side of the substrate body is buffed utilizingthe buffing agent which forms a plurality of scratches in the first sideaccording to the particular grit of the agent. The scratches define thediffuser surface and thereby exhibit light propagating characteristicsdefined by the orientation, contour, length and depth of the pluralityof irregularities.

[0015] In another embodiment, the working material is an acid or alkaliagent selected to react with a particular substrate body material. Theacid or alkali agent is placed on the first side of the substrate bodyfor an etching time duration. The acid or alkali agent etches aplurality of irregularities into the first side of the substrate body.The plurality of irregularities each have at least a size, a depth, anda contour formed according to the reaction between the substrate bodyand the acid or alkali agent as well as etching time duration. Thediffuser surface on the first side exhibits light propagationcharacteristics defined by the size, depth and contour of theirregularities formed by the etching or acid or alkali agent.

[0016] In another embodiment, the acid or alkali etching agent alsoincludes a plurality of particles mixed therein each having a size, ashape and a mass. The particles enhance the etching reaction between thesubstrate body and the acid or alkali agent by forming deeperdepressions where the particles are located on the first side of thesubstrate body. In another embodiment, a pressure may be applied to thefirst side of the substrate body while the acid or alkali agent andparticles are disposed thereon to further enhance penetration of theparticles into the first side of the substrate body as the acid oralkali agent reacts with the substrate body material.

[0017] In one embodiment, a mask having a plurality of openings formedtherein is applied to the first side of the substrate body. The acid oralkali agent is placed on the first side over the mask and therebyetches a plurality of irregularities into the first side where the firstside is exposed through the openings of the mask. The irregularitieseach have a size, depth and contour which are essentially determined bythe length, width, orientation and shape of the plurality of openings inthe mask as well as the particular reaction between the acid agent andthe substrate body as well as the etching time duration.

[0018] In one embodiment, the working material is a blasting agent whichincludes a plurality of shot particles each having a size, a shape and amass. The blasting agent is forced against the first side of thesubstrate body such as in a sandblasting operation at a predeterminedvelocity to form a plurality of irregularities or depressions. Thedepressions are formed according to the size, shape and mass of the shotparticles as well as the predetermined velocity. The diffuser surfacestructure is defined by the depth, contour and size of the plurality ofirregularities formed in the first side of the substrate body.

[0019] In another embodiment of the invention, a diffuser is disclosedhaving a substrate body and at least a first side. A diffuser surfacerelief structure formed non-holographically in the first side defines aplurality of irregularities therein. The irregularities have lightpropagating characteristics which are defined by at least one of thesize, depth, length, width, orientation, and contour of the plurality ofirregularities.

[0020] In one embodiment, the substrate body is formed from a glassmaterial substrate. In another embodiment, the substrate body is formedfrom a hard plastic material substrate. In another embodiment, thesubstrate body is formed from a metallic material substrate.

[0021] In one embodiment, the surface relief structure is comprised of aplurality of scratches formed by buffing the first side with a buffingagent having a predetermined grit. In another embodiment, the surfacerelief structure is comprised of a plurality of closely spaceddepressions in the first side formed by forcing a plurality of shotparticles at a predetermined velocity against the first side. In afurther embodiment, the surface relief structure is acid etched into thefirst side by an acid agent placed on the first side of the substratebody.

[0022] These and other aspects and objects of the present invention willbe better appreciated and understood when considered in conjunction withthe following description and accompanying drawings. It should beunderstood, however, that the following description, while indicatingpreferred embodiments of the present invention, is given by way ofillustration and not of limitation. Many changes and modifications maybe made within the scope of the present invention without departing fromthe spirit thereof and the invention includes all such modifications.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] A clear conception of the advantages and features of the presentinvention, and of the construction and operation of typical mechanismsprovided with the present invention, will become more readily apparentby referring to exemplary and therefore non-limiting embodimentsillustrated in the drawings accompanying and forming a part of thisspecification, and in which:

[0024]FIG. 1A illustrates an elevational perspective view of a glassdiffuser constructed in accordance with one embodiment of the presentinvention;

[0025]FIG. 1B illustrates an elevational perspective view of a metaldiffuser constructed in accordance with another embodiment of thepresent invention;

[0026]FIG. 1C illustrates an elevational perspective view of a plasticdiffuser constructed in accordance with another embodiment of thepresent invention;

[0027]FIG. 2 illustrates a schematic view of a buffing process forforming one of the diffusers of FIGS. 1A-1C;

[0028]FIG. 3 illustrates a schematic view of an etching process forforming one of the diffusers illustrated in FIGS. 1A-1C;

[0029]FIG. 4 illustrates an alternative etching process for forming oneof the diffusers illustrated in FIGS. 1A-1C;

[0030]FIG. 5A illustrates another alternative etching process forforming one of the diffusers illustrated in FIGS. 1A-1C;

[0031]FIG. 5B illustrates a perspective view of the diffuser illustratedin FIG. 5A;

[0032]FIG. 6 illustrates a schematic view of a blasting process forforming one of the diffusers illustrated in FIGS. 1A-1C;

[0033]FIG. 7A illustrates an elevational plan view of the diffusersurface of a diffuser; and

[0034]FIG. 7B illustrates a cross-sectional view of the diffuser surfacetaken along lines 7B-7B of FIG. 7A.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0035] Referring now to the drawings, FIGS. 1A-1C illustrate severalsimplified elevational perspective views of diffusers formed by one ofthe methods of the present invention. The present invention may beutilized to form diffusers from substrate materials such as plastics,glass or metal. The methods are appropriate for forming diffusers fromconventional diffuser materials such as epoxy, polycarbonate, polyester,acrylic, nylon, polystyrene, tetrafluoroethylene, polyimide, polyvinylchloride, polymethyl methacrylate, TPX™, ARTON™, and other plasticmaterials but also may be utilized to form diffusers from much moredurable materials such as glass and metal for which previous methodswere not suitable. Glass materials that can be used include light bariumcrown, phosphate crown, crown, flint, extralight flint, light flint,fused silicon, and borosilicate. FIG. 1A illustrates a glass diffuser 20constructed according to one embodiment of the present invention. FIG.1B illustrates a metal diffuser 22 constructed in accordance with oneembodiment of the present invention. FIG. 1C illustrates a plasticdiffuser 24 constructed in accordance with one embodiment of the presentinvention. The glass diffuser 20, metal diffuser 22, and plasticdiffuser 24 will be described in greater detail below with reference tothe processes of the invention.

[0036]FIG. 2 illustrates a schematic view of a process of forming arandom surface relief structure on a diffuser substrate body. Thesubstrate body 30 includes a first side 32 onto which a diffuser surfacerelief structure will be formed. The substrate 30 is illustrated in theform of a flat rectangular plate and the diffusers 20, 22 and 24 areillustrated in the form of rectangles in FIGS. 1A-1C. It is intendedthat the diffusers and the substrate material may take on any number ofconfigurations and constructions without departing from the scope of thepresent invention. The simple shapes and configurations illustratedherein are shown for simplification of description and not by way oflimitation.

[0037] The substrate 30 of the present embodiment can also be in theform of a glass substrate, a metal substrate, or a plastic substratewithout departing from the scope of the present invention. Dependingupon the type of substrate material selected, the process shown in FIG.2 may vary slightly in order to produce the desired surface reliefstructure as described below. The method of the invention is capable offorming a surface relief structure on a common material such as plasticbut is also capable of forming such a surface relief structure on hardand highly durable materials such as glass and metal. Prior methods offorming diffuser surface relief structures are not capable of producingsuitable surface relief structures on such hard and durable materials.

[0038] Referring again to FIG. 2, the first side 32 of the substrate 30is facing upward although this orientation can be altered withoutdeparting from the scope of the invention. The substrate 30 can also beheld in a suitable fixture (not shown) or other apparatus for affixingthe substrate in place while it is being worked.

[0039] As illustrated in FIG. 2, a suitable buffing agent 34 is disposedon the first side 32 of the substrate 30. Buffing agents that can beused include agents such as aluminum oxide, silicon carbide, and ceriumoxide. A buffing apparatus 36 is disposed over the substrate 30 and isutilized to work the buffing agent 34 against the first side 32 toproduce scratches or other such irregularities in the substrate firstside 32. Depending upon the materials selected for the substrate 30, thebuffing agent is selected including a particular grit in the form ofbuffing particles 35 which are suspended within a compound or which areotherwise attached to the buffing apparatus 36. The buffing particles 35are determined by the type of substrate material 30 selected.

[0040] For example, if the substrate 30 is a plastic material, thebuffing agent 34 may be a buffing compound having suspended therein aplurality of buffing particles 35 in the form of sand or silica of aparticular grit or size. Alternatively, the buffing agent can be in theform of what is commonly known as sandpaper which includes a papersubstrate having sand or silica particles adhered thereto of aparticular grit. In either case, the buffing particles must be suitablefor working and abrading the surface of the relatively soft plasticsubstrate.

[0041]FIG. 2 illustrates that a buffing agent 34 including suspendedsilica particles is disposed on the first side 32 of the substrate 30.The buffing apparatus 36 includes a buffing pad 38 that is brought intocontact with the buffing compound 34 and rotated or otherwise movedagainst the buffing compound 34. The buffing pad 38 works the buffingagent 34 including the suspended silica particles into the first side 32to form a plurality of surface irregularities in the form of scratchesand indentations in the surface. In an alternative embodiment, thebuffing apparatus 36 may have a sheet or pad of sandpaper mounted to thepad 38, where the sheet includes the silica particles adhered thereto.In this embodiment, the buffing compound 34 is not necessary and isreplaced by the sandpaper carried on the buffing pad 38.

[0042]FIG. 2 illustrates that the buffing pad 38 is rotated about arotary shaft 40 in order to work the buffing agent 34 into the firstside 32. The buffing pad 38 can alternatively be a surface which movesback and forth across the first side 32 in order to produce thescratches and indentations. In a further alternative, the buffing pad 38can be connected via a mechanism (not shown) and electronic means to acomputer system 42 for guiding the buffing pad 38 over the first side32. In such an embodiment, the particular surface scratches andindentations are preprogrammed into the computer and replicated onto thefirst side 32 as desired.

[0043] In this embodiment, the surface irregularities, indentations orscratches are formed in the first side 32 of the substrate 30 by thesilica or buffing particles of the buffing agent 34 physically cuttinginto the first side 32. The depth, cross-sectional contour, length andshape of the scratches depends on the direction of rotation and/orlinear movement of the buffing pad 38 of the buffing apparatus 36relative to the first side of the substrate.

[0044] If the substrate body 30 is alternatively formed from a materialsuch as glass or a very hard plastic or a soft metal such as gold, thebuffing agent 34 may include a more durable type of sand or silicaparticle 35 is suitable for forming scratches and indentations andotherwise deforming such hard materials. Alternatively, if the substratematerial is any type of glass including extremely hard composite glass,the buffing agent 34 may include buffing particles 35 in the form of adiamond powder or diamond particles suitable for scratching or otherwisedeforming such a hard surface. The type of buffing agent 34 as well asthe particular construction of the buffing apparatus 36 is selected anddesigned according to the desired diffuser characteristics and thesubstrate 30 material.

[0045] Referring now to FIG. 3, a substrate body 50 includes a firstside onto which a surface relief structure is to be formed. Again, thesubstrate material can be any suitable material but preferably is ametal or glass substrate material. Additionally, the substrate 50 can besupported in a suitable fixture or machine (not shown) in order toperform the process of the invention.

[0046] An acid or alkali etching agent 54, such as hydrochloric acid,hydrofluoric acid, ammonium fluoride, potassium hydroxide or sodiumhydroxide is poured on or otherwise disposed over the first side 52 ofthe substrate 50. The etching agent 54 reacts with the substratematerial and forms irregularities or depressions in the first side 52 todefine the diffuser surface relief structure as is described in moredetail below. The etching acid or alkali can be any type of acid oralkali that is selected to react as desired with a particular substratematerial from which the substrate body 50 is manufactured. The etchingacid in one preferred embodiment is a solution containing eitherhydrofluoric acid or ammonium fluoride. The etching alkali in onepreferred embodiment is a solution containing either potassium hydroxideor sodium hydroxide. Depending on the amount of time the acid or alkaliis left on the first side of the substrate and on the concentration ofthe acid or alkali, the etching agent 54 reacts with the first side toform the irregularities thereon. The etching acid or alkali essentiallyeats away at the surface of the substrate body 50 where it is locatedand where it is most concentrated. For example, the etching acid oralkali can be applied to the first side 52 for less than 2 minutes on aglass or metal substrate body 50 to produce the desired result.

[0047] After the desired duration of acid or alkali etching has expired,the first side 52 is washed with water or another cleaning solution inorder to remove all of the remaining etching agent 54. A suitable hose58 connected to a reservoir of water other solution 60 can be retainednear the substrate 50 in order to wash the etching agent 54 from thesubstrate.

[0048] In the present embodiment, a plurality of solid particles 56 aresuspended in the acid or alkali etching agent 54 to further enhance theetching process and to produce a more desirable surface relief structurein the first side 52 of the substrate. Alternatively, the particles canbe first placed on top of the substrate body 50, such as a glasssubstrate, and then the etching agent 54 poured over the first side 52and the particles 56 to produce the desired surface relief. Theparticles 56 enhance the surface relief structure by penetrating deeperinto the first side 52 according to the mass and size of each particleand according to the chemical reaction between the etching agent 54 andthe substrate body 50 beneath each particle. The greater the mass ofeach particle 56, the deeper the depression left beneath each particularparticle.

[0049]FIG. 4 illustrates another alternative embodiment of the acid oralkali etching process whereby a pressure plate or pressing tool 62 isplaced over the first side 52 sandwiching therebetween the acid oralkali etching agent 54 and the particles 56. A force in the directionof arrows F is applied to the pressure plate or pressing tool 62 toincrease penetration of the particles deeper into the first side 52. Themore force applied to the plate 62, the deeper the particles 56 willembed into the first side 52 thereby enhancing the surface reliefstructure.

[0050] The size, shape and mass of the particular particles 56 can varyconsiderably depending on the desired surface relief characteristicsformed in the first side 52. In one embodiment, a powder such as aceramic powder including very fine particles can be utilized and placedon the first side 52 of the substrate body 50. The ceramic powderparticles are particularly useful for etching a substrate of glass.Particular examples of suitable powder particles include silicon carbideand boron carbide. Such powder particles can either be in the form ofirregular and randomly shaped particles in a range of sizes from about 4mm to about 0.045 mm. Alternatively, particles can have a general shapeof hexagonal, rhombohedral, spherical, or any other suitable shape andrange in sizes from about 4 mm to about 0.045 mm. The larger theparticle size, the deeper the impression made in the first side 52.Spherical particles 56 will leave essentially semi-circular or sphericaldepressions in the first side 52.

[0051]FIGS. 5A and 5B illustrate another alternative embodiment whichcan be utilized to etch a surface relief structure in a substrate body50. FIG. 5B illustrates a perspective view of substrate body 50 and themask 64. In this embodiment, a mask 64 made of a material such aspolyester or polycarbonate is placed over the first side 52 of thesubstrate body 50. A portion of the first side 52 is exposed through aplurality of openings 66 formed in the mask 64. The openings 66 can berandomly produced in the mask or can be computer generated in order toproduce a particular and predetermined surface relief structure in thesubstrate body 50.

[0052] In this embodiment, the etching agent 54 does not necessarilyinclude particles 56 therein but may instead be a purely liquidsolution. The etching acid solution 54 is then poured over the mask 66and etches the first side 52 of the substrate body 50 only where exposedthrough the openings 66. The surface contour and configuration of thesurface relief structure formed on the first side 52 is determined bythe length, width, contour, spacing and shape of the openings 66provided in the mask 64 as well as the acid concentration, duration andetching and acid and substrate compositions. Virtually any pattern ofopenings can be produced in the mask 64 to form any number of surfacerelief structures in the substrate body 50.

[0053] Referring now to FIG. 6, another alternative embodiment forproducing a surface relief structure in a substrate body is disclosed.In this embodiment, a substrate body 70 is provided having a first side72 onto which a diffuser surface relief structure is to be formed. Thesubstrate body 70 is placed adjacent a blasting apparatus 74 having anozzle 76 from which a blasting material is ejected at a high velocityin the direction of the arrows B toward the first side 72 of thesubstrate. A hose 78 is connected to a supply (not shown) of blastingmaterial or particles 80 drawn into the hose 78 of the apparatus 74 andejected toward the substrate. The particles 80 can be in the form ofshot particles and may be provided from any number of materials such asspherical metal balls or sand or silica particles of various sizes andshapes. The particles 80 are ejected from the blasting apparatus 74 andbombard the first side 72 of the substrate. Upon impact with thesubstrate, the particles 80 form small depressions or pits in the firstside. These depressions or pits define the surface relief structure ofthe diffuser created on the substrate 70. The shape, size and contour ofthe depressions or pits are defined by the mass, size and shape of theshot particles 80, the velocity of the particles exiting the nozzle 76,and the material which forms the particles and the substrate body 70.Additionally, the angle of incidence of the nozzle 76 relative to thefirst side 72 and the path of travel of the shot particles 80 relativeto the first side 72 also affects the structure formed on the firstside. Additionally, the size and shape of the nozzle 76 may also bevaried in order to change the surface relief structure characteristicsformed on the first side of the substrate.

[0054] Referring now to FIG. 7A, an elevation plan view of a diffuserand a diffuser surface formed by any of the above embodiments isillustrated. The diffuser has a substrate 30, 50, or 70 and a diffusersurface 33, 53, or 73 formed by the buffing, etching, and blastingembodiments, respectively. FIG. 7B illustrates a cross-sectional view ofthe diffuser surface taken along lines 7B-7B of FIG. 7A.

[0055] The shape and orientation of the scratches and indentationsdetermine the light output characteristics of the diffuser, includingnon-Lambertian output. For example if the scratches are long and narrowin one direction the light output from the diffuser will be adistribution which is long and narrow in the perpendicular direction.If, for example, a circular light distribution is desired, scratches orindentations of a more circular shape, such as might be achieved bypressing the buffing material into the surface in the presence of acid,are preferably used.

[0056] Though the invention was described referring to particularembodiments, many other changes and modifications may be made to theinvention as described without departing from the spirit and scopethereof. The scope and spirit of these changes and modifications willbecome apparent from the appended claims. The scope of the invention istherefore intended only to be limited by the appended claims.

What is claimed is:
 1. A method of making a non-Lambertian diffuser, themethod comprising the steps of: providing a substrate body having atleast a first side; selecting a buffing agent having a desired grit; andbuffing the first side of the substrate body with the buffing agent toform a plurality of irregularities in the first side according to thegrit of the buffing agent to thereby form a diffuser surface havinglight propagating characteristics defined by the orientation, contourand depth of the plurality of irregularities.
 2. The method according toclaim 1 , wherein the step of providing further includes providing asubstrate body from a plastic material selected from one of the groupconsisting of at least polycarbonate, polyester, acrylic, nylon,polystyrene, tetrafluoroethylene, polyimide, polyvinyl chloride,polymethyl methacrylate, TPX™, and ARTON™.
 3. The method according toclaim 1 , further comprising the step of: placing the buffing agentdirectly on the first side of the substrate body prior to the step ofbuffing.
 4. The method according to claim 1 , farther comprising thesteps of: placing the buffing agent on a buffing apparatus; moving thebuffing apparatus into contact with the first side of the substratebody; and buffing the first side with the buffing apparatus.
 5. Themethod according to claim 1 , wherein the step of selecting furtherincludes selecting a buffing agent from at least one of the groupconsisting of aluminum oxide, silicon carbide, and cerium oxide.
 6. Amethod of making a non-Lambertian diffuser, the method comprising thesteps of: providing a substrate body having at least a first side;selecting an etching agent; placing the etching agent on the first sideof the substrate body for an etching time duration; and etching aplurality of irregularities into the first side, the plurality ofirregularities having at least a size, a depth and a contour formedaccording to a reaction between the substrate body and the etching agentand according to the etching time duration to thereby form a diffusersurface on the first side having light propagation characteristicsdefined by the size, depth and contour of the irregularities.
 7. Themethod according to claim 6 , wherein the step of providing furtherincludes providing a substrate body formed from a glass material.
 8. Themethod according to claim 6 , wherein the step of providing furtherincludes providing a substrate body formed from a glass materialselected from at least one of the group consisting of light bariumcrown, phosphate crown, crown, flint, extralight flint, light flint,fused silica, and borosilicate.
 9. The method according to claim 6 ,wherein the step of selecting further includes selecting an etchingagent from at least one of the group consisting of sodium hydroxide,potassium hydroxide, hydrofluoric acid, and ammonium fluoride.
 10. Themethod according to claim 6 , further comprising the steps of: mixing aplurality of solid particles with the acid agent to form a workingcompound, each of the plurality of particles having a size, a shape anda mass; and etching the plurality of irregularities into the first side,the size, depth and contour of the plurality of irregularitiesdetermined by the size, shape and mass of the plurality of particles aswell as the reaction between the etching agent and the substrate bodyand the etching time duration.
 11. The method according to claim 10 ,further comprising the step of: applying pressure against the first sideafter the step of placing the working compound thereon in order toincrease the depth of the plurality of irregularities.
 12. The methodaccording to claim 10 , wherein the step of mixing further includesproviding a plurality of particles each having a general shape selectedfrom the group consisting of hexagonal, rhombohedral, and spherical, anda diameter within a range of diameters from about 4 mm to about 0.045mm.
 13. The method according to claim 11 , wherein the plurality ofparticles are provided having a number of different diameters, thediameter of each of the plurality of particles being within the range ofdiameters.
 14. The method according to claim 10 , wherein the step ofmixing further includes providing the plurality of particles selectedform at least one of the group consisting of silicon carbide and boroncarbide.
 15. The method according to claim 6 , further comprising thesteps of: selecting a mask having a plurality of openings passingthrough the mask, each of the plurality of openings having a length, awidth, an orientation and a shape; securing the mask flush against thefirst side of the substrate body; placing the etching agent over themask on the first side; and etching the plurality of irregularities intothe first side of the substrate body whereby the size, depth and contourof the plurality of irregularities are determined by the length, width,orientation and shape of the plurality of openings in the mask as wellas the reaction between the etching agent and the substrate body and theetching time duration.
 16. The method according to claim 15 , whereinthe step of selecting a mask further includes selecting a mask made froma material selected from the group consisting of polyester andpolycarbonate.
 17. A method of making a non-Lambertian diffuser, themethod comprising the steps of: providing a substrate body having atleast a first side; selecting a blasting agent including a plurality ofshot particles each having a size, a shape and a mass; and forcing theblasting agent against the first side of the substrate body at apredetermined velocity to form a plurality of irregularities in thefirst side according to the size, shape and mass of the plurality ofshot particles and the predetermined velocity to thereby form a diffusersurface structure in the first side according to a depth, contour andsize of the plurality of irregularities.
 18. The method according toclaim 17 , wherein the step of providing further includes providing asubstrate body formed from a glass material.
 19. The method according toclaim 17 , wherein the step of providing further includes providing asubstrate body formed from a glass material selected from at least oneof the group consisting of light barium crown, phosphate crown, crown,flint, extralight flint, light flint, fused silica, and borosilicate.20. The method according to claim 17 , wherein the step of providingfurther includes providing a substrate body formed from a metalmaterial.
 21. The method according to claim 17 , wherein the step ofselecting further includes selecting the plurality of shot particleseach having a diameter within a range from about 4 mm to about 0.045 mmand a general shape selected from the group consisting of hexagonal,rhombohedral, and spherical.
 22. The method according to claim 17 ,wherein the step of selecting further includes selecting the pluralityof shot particles from shot particles made from a metal material.
 23. Anon-Lambertian diffuser comprising: a substrate body having at least afirst side; and a diffuser surface relief structure formednon-holographically in the first side, the surface relief structuredefining a plurality of irregularities in the first side and havinglight propagating characteristics defined by at least one of the size,depth, length, width, orientation, and contour of the plurality ofirregularities.
 24. The diffuser according to claim 23 , wherein thesubstrate body is a glass material substrate.
 25. The diffuser accordingto claim 23 , wherein the substrate body is a plastic materialsubstrate.
 26. The diffuser according to claim 23 , wherein thesubstrate body is a metallic material substrate.
 27. The diffuseraccording to claim 23 , wherein the surface relief structure comprises aplurality of scratches in the first side formed by buffing the firstside with a buffing agent having a predetermined grit, each of theplurality of scratches having a depth, a contour, a length, a width, anda shape.
 28. The diffuser according to claim 23 , wherein the surfacerelief structure comprises a plurality of closely spaced depressions inthe first side each having a depth and a contour and each formed byforcing a plurality of shot particles at a predetermined velocityagainst the first side, the shot particles each having a predeterminedsize, shape and mass.
 29. The diffuser according to claim 23 , whereinthe surface relief structure is etched into the first side by an etchingagent carrying a plurality of particles each having a size, shape andmass.
 30. The diffuser according to claim 29 , wherein the surfacerelief structure is further etched into the first side by pressing theplurality of particles into the first as side.
 31. The diffuseraccording to claim 23 , wherein the surface relief structure is furtheretched into the first side by an etching agent contacting the first sidethrough a plurality of openings in a mask, the plurality of openingseach having a length, a width, an orientation and a shape.